Gather three bowls and all your ingredients for the breading. In the first bowl, whisk the flour, salt, and pepper together. In the second bowl, whisk together the non-dairy milk and vinegar. In the third bowl, whisk the bread crumbs, garlic, and red pepper flakes.
Take a mozzarella stick, dip it in the non-dairy milk, then coat it in the flour mixture, then back in the milk, back in the flour, back in the milk, and then coat it completely in the bread crumbs. Set on a plate or piece of parchment paper.
Repeat the process with all of the mozzarella sticks.
Chill the mozzarella sticks for about 5-10 minutes while you heat the oil.
Heat about 2 inches of vegetable oil in a saucepan or skillet on medium-high, until it reaches about 350 degrees(F). It should have tiny bubbles forming.
Add a few mozzarella sticks to the hot oil at a time, fry for 2-3 minutes per side, or until the mozzarella sticks are golden brown. Reduce heat as needed. Lay the mozzarella sticks on a paper towel, and fry the remaining mozzarella sticks.
Make the Nashville hot sauce. Heat the vegan butter, cayenne, brown sugar, paprika, agave, and a pinch of salt and pepper in a medium-sized saucepan. Heat on medium, whisking until everything has melted together. About 3-5 minutes. Let simmer for 2-3 more minutes.
Toss the mozzarella sticks in the hot sauce, and serve immediately with vegan ranch.